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Methods and apparatus for determining the status of a device

  • US 8,249,953 B2
  • Filed: 07/13/2004
  • Issued: 08/21/2012
  • Est. Priority Date: 05/13/2004
  • Status: Active Grant
First Claim
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1. A method, comprising:

  • instructing by a network device a first radio frequency identification (“

    RFID”

    ) device to transmit heartbeat packets, wherein instructing by the network device is performed by sending one or more commands including provisioning information to the first RFID device, wherein the provisioning information specifies a frequency of the heartbeat packets that the first RFID device is to transmit, each of the heartbeat packets a first Electronic Product Code (“

    EPC”

    ) of the first RFID device and a time stamp, wherein the EPC of the first RFID device indicates that the first RFID device transmitted the heartbeat packet and the time stamp indicates a time that the heartbeat packet was transmitted by the first RFID device, wherein the one or more commands further indicate a first time at which the first RFID device is to transmit a first one of the heartbeat packets; and

    determining by the network device whether the first RFID device transmitted the first one of the heartbeat packets;

    wherein sending one or more commands comprises sending one or more command packets including the provisioning information to the first RFID device;

    wherein the network device does not transmit the heartbeat packets.

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